The invention relates to a method for determining a NOx concentration in a measurement gas, wherein a sensor signal of a gas sensor that is sensitive for NOx and is brought into contact with the measurement gas is captured and a measurement value for the NOx concentration is determined from the sensor signal, and to a device for carrying out this method.
Such methods are already known, wherein chemiluminescence detectors (CLD) are preferably used as the gas sensors. For example, such methods are used for testing legal limit values, for example, for determining the specific nitrogen oxide emission as an exhaust gas characteristic of a combustion engine, but these methods are also used in other applications.
Legal limit values for nitrogen oxide content in a measurement gas, for example, the exhaust gas of a combustion engine, have often been established for reasons of climate protection or for other political reasons, wherein sanctions can be imposed for non-compliance. Such regulations often refer to a specifically predetermined measurement method, in order to rule out legal uncertainties.